Color photography workers who develop color film require a plurality of heated chemical fluids to develop the film. At the present time, in the photography arts, chemicals are heated by first heating a tank with hot water poured into the tank, removing the water when the water is at the desired temperature, and then pouring the chemical into the tank to absorb the heat stored therein. This is clearly an undesirable procedure. Immersion heaters might be used, with one being provided, preferably, for each chemical to be heated. If only one immersion heater were employed, it would have to be washed after each separate heating operation. In addition, care must be taken with immersion heaters since they burn up if removed from the fluid without being disconnected.